Boss Roberto De Zerbi was not surprised to see World Cup winner Alexis Mac Allister come off the bench to cement Brighton's place in the FA Cup fourth round.
David Moyes hopes West Ham's FA Cup win at Brentford will be a turning point in their season.
Two brilliant goals were unable to prevent FA Cup holders Liverpool from starting their FA Cup defence with an unconvincing 2-2 draw against Wolves.
Harry Kane scored for Tottenham with the only goal of the game to sink Portsmouth in the FA Cup.
Kelechi Iheanacho extended his fine FA Cup record by firing Leicester into the fourth round with the second-half winner in a 1-0 victory at League Two strugglers Gillingham.
Marcus Rashford scored his fifth goal in as many games after creating two others to help Manchester United into the fourth round of the FA Cup with a 3-1 win over Everton.